<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>

    <div id="app">
        姓：<input type="text" v-model="firstName"><br>
        名：<input type="text" v-model="lastName"><br>
        <p>姓名：{{ fullName }}</p>
        <button @click="changeName">修改姓名</button>
    </div>
    <script src="../utils/vue.js"></script>
    <script>
        const app = new Vue({
            el: '#app',
            data: {
                firstName: '刘',
                lastName: '备'
            },
            computed: {
                fullName: {
                    get() {
                        return this.firstName + this.lastName
                    },
                    set(value) {
                        this.firstName = value.slice(0, 1)
                        this.lastName = value.slice(1)
                    }
                }
            },
            methods: {
                changeName() {
                    this.fullName = '吕小布'
                }
            }
        })
    </script>
</body>
</html>